scholarly journals Impact of Fast High-Intensity versus Conventional Light-Curing Protocol on Selected Properties of Dental Composites

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1381
Author(s):  
Sufyan Garoushi ◽  
Lippo Lassila ◽  
Pekka K. Vallittu
Keyword(s):  
High Intensity ◽  
Composite Resin ◽  
Light Transmission ◽  
Wear Test ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Ftir Spectrometry ◽  
Double Bond Conversion ◽  
Light Curing ◽  
Chewing Simulator

To study the influence of fast high-intensity (3-s) and conventional (20-s) light curing protocols on certain physical properties including light-transmission and surface wear of two nano-hybrid composite resins (Tetric PowerFill and Essentia U) specifically designed for both curing protocols. According to ISO standards, the following properties were investigated: flexural properties, fracture toughness and water sorption/solubility. FTIR-spectrometry was used to calculate the double bond conversion (DC%). A wear test using a chewing simulator was performed with 15,000 chewing cycles. A tensilometer was used to measure the shrinkage stress. Light transmission through various thicknesses (1, 2, 3 and 4 mm) of composite resins was quantified. The Vickers indenter was utilized for evaluating surface microhardness (VH) at the top and the bottom sides. Scanning electron microscopy was utilized to investigate the microstructure of each composite resin. The light curing protocol did not show a significant (p > 0.05) effect on the mechanical properties of tested composite resins and differences were material-dependent. Shrinkage stress, DC% and VH of both composite resins significantly increased with the conventional 20 s light curing protocol (p < 0.05). Light curing conventional composite resin with the fast high-intensity (3-s) curing protocol resulted in inferior results for some important material properties.

scholarly journals Comparison of silorane and methacrylate-based composite resins on the curing light transmission

2010 ◽  
Vol 21 (6) ◽  
pp. 538-542 ◽  
Author(s):  
Ricardo Danil Guiraldo ◽  
Simonides Consani ◽  
Rafael Leonardo Xediek Consani ◽  
Sandrine Bittencourt Berger ◽  
Wilson Batista Mendes ◽  
...  
Keyword(s):  
Composite Resin ◽  
Light Transmission ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Power Meter ◽  
Light Curing ◽  
Curing Light ◽  
The Mean ◽  
Spectral Distributions ◽  
The Difference

The aim of this study was to investigate the influence of different composite resins - Filtek P90 (silorane-based composite) and Heliomolar (methacrylate-based composite) - on light transmission and decrease in Knoop hardness between the bottom and top of cured specimens. The irradiance of a light-curing unit (LCU) was measured with a power meter (Ophir Optronics; 900 mw/cm2) and spectral distributions were obtained using a spectrometer (USB 2000). Twenty standardized cylindrical specimens (2 mm thick x 7 mm diameter) of each composite resin were obtained by curing using the LCU for 40 s. Light energy transmission through the composite was calculated (n=10). The Knoop hardness number for each surface was recorded as the mean of 3 indentations. The difference in Knoop hardness between the top and bottom (DKH) of the same specimen was calculated (n=10). The irradiance of light that passed through Filtek P90 (272 mW/cm2) was not significantly greater than that the passed through Heliomolar (271 mW/cm2). The DKH of Filtek P90 (25%) was significantly higher than that of Heliomolar (12%). There was a greater degree of subsurface polymerization of the methacrylate-based composite compared to the silorane-based composite.

Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin

2007 ◽  
Vol 8 (6) ◽  
pp. 1-8 ◽  
Author(s):  
José Roberto Lovadino ◽  
Gláucia Maria Bovi Ambrosano ◽  
Flávio Henrique Baggio Aguiar ◽  
Aline Braceiro ◽  
Débora Alves Nunes Leite Lima
Keyword(s):  
Hybrid Composite ◽  
High Intensity ◽  
Composite Resin ◽  
Resin Composite ◽  
Composite Resins ◽  
Bottom Surface ◽  
Curing Time ◽  
Experimental Conditions ◽  
Light Curing ◽  
Effect Of Light

Abstract Aims The aim of this in vitro study was to evaluate the influence of light curing modes and curing time on the microhardness of a hybrid composite resin. Methods and Materials Forty-five Z250 composite resin specimens (3M-ESPE Dental Products, St. Paul, MN, USA) were randomly divided into nine groups (n=5): three polymerization modes (conventional - 550 mW/ cm2; light-emitting diodes (LED) - 360mW/cm2, and high intensity - 1160 mW/cm2) and three light curing times (once, twice, and three times the manufacturer's recommendations). All samples were polymerized with the light tip 8 mm from the specimen. Knoop microhardness measurements were obtained on the top and bottom surfaces of the sample. Results Conventional and LED polymerization modes resulted in higher hardness means and were statistically different from the high intensity mode in almost all experimental conditions. Tripling manufacturers’ recommended light curing times resulted in higher hardness means; this was statistically different from the other times for all polymerization modes in the bottom surface of specimens. This was also true of the top surface of specimens cured using the high intensity mode but not of conventional and LED modes using any of the chosen curing times. Top surfaces showed higher hardness than bottom surfaces. Conclusions It is important to increase the light curing time and use appropriate light curing devices to polymerize resin composite in deep cavities to maximize the hardness of hybrid composite resins. Citation Aguiar FHB, Braceiro A, Lima DANL, Ambrosano GMB, Lovadino JR. Effect of Light Curing Modes and Light Curing Time on the Microhardness of a Hybrid Composite Resin. J Contemp Dent Pract 2007 September; (8)6:001-008.

scholarly journals Influence of composite resin volume and C-factor on the polymerization shrinkage stress

2016 ◽  
Vol 19 (2) ◽  
pp. 72 ◽  
Author(s):  
Rafael Francisco Lia Mondelli ◽  
Marilia Mattar de Amoêdo Campos Velo ◽  
Rafael Simões Gonçalves ◽  
Bhenya Ottoni Tostes ◽  
Sergio Kiyoshi Ishikiriama ◽  
...  
Keyword(s):  
Composite Resin ◽  
In Vitro Study ◽  
Composite Resins ◽  
Steel Plates ◽  
Shrinkage Stress ◽  
Lower Stress ◽  
Polymerization Shrinkage ◽  
Light Curing ◽  
Clinical Problems

<p>Objective: Composite polymerization shrinkage<br />stress is an inherent process of chemical and light<br />composite resin activation. Consequently, this fact has<br />been associated to potential clinical problems. The<br />aim of the present in vitro study was to evaluate the<br />volume and C-factor influence on chemical and lightcuring<br />composite resin polymerization shrinkage<br />stress, using a non-rigid method that thereby provides<br />lower stress values, causing a minimal deflection in<br />load cell. Materials and Methods: The contraction<br />forces of the Z-250 and Concise composite resins<br />during polymerization were recorded in an UTM in<br />two experiments. In the first experiment, the Z-250<br />composite was inserted beetwen two rectangular<br />steel plates (6.0 x 2.0 mm), varyng the resin volumes<br />and C-factors, in a single increment, polymerized for<br />20 s and the forces generated were recorded for 120<br />s. In the second experiment, a pair of rectangular steel<br />plates (3x2mm) and two square steel plates (2x2mm),<br />with varied heights (2; 3 mm, respectively), were<br />used to determine the C-factor (0.6; 0.3) influence.<br />Results: The polymerized Z-250 results showed that<br />the volume variations, independent of the C-factor,<br />had a direct influence on the shrinkage stress,<br />different from the Concise, which was influenced by<br />the C-factor. Conclusion: The present study showed<br />that a higher volume of composite resins determines<br />an increase in the shrinkage stress of light-curing<br />composites.</p><p><strong>Keywords</strong></p><p>C-factor. Composite resin. Polymerization. Shrinkage<br />stress.</p>

scholarly journals THE COMPARISON OF RESIN-BASED COMPOSITES PHYSICAL PROPERTIES BETWEEN BULK-FILL TECHNIQUE AND INCREMENTAL TECHNIQUE

2021 ◽  
Vol 6 (1) ◽  
pp. 85
Author(s):  
Rahmi Khairani Aulia
Keyword(s):  
Physical Properties ◽  
Composite Resin ◽  
Color Stability ◽  
Composite Resins ◽  
Shrinkage Stress ◽  
Restorative Material ◽  
Polymerization Shrinkage ◽  
Advantages And Disadvantages ◽  
Restoration Technique ◽  
Restoration Failure

ABSTRACT:Composite resins are currently the most popular restorative material in dentistry. This is due to good aesthetics and maximum conservation ability. Behind these advantages, there are disbenefits of composite resin materials, such as polymerization shrinkage, which can lead to restoration failure. Various attempts have been investigated to reduce the shrinkage incidence of composite resins, one of which is the technique of placing the restorative material into the cavity. The restoration filling technique is recognized as a significant factor in shrinkage stress. By using a special filling technique, the polymerization shrinkage damage stress can be reduced. There are several techniques in performing composite resin fillings, including bulk and incremental techniques. These techniques have their respective advantages and disadvantages. The aim of this literature review was to compare the physical properties of composite resin restorations with bulk filling and incremental techniques. Physical properties that being studied include polymerization shrinkage, stress shrinkage, degree of conversion, bonding strength, water resorption, color stability, and temperature increase. Comparing the two techniques, composite resin with incremental filling technique has superior physical properties compared to bulk technique. From the comparison of the two techniques, the composite resin with incremental filling technique has superior physical properties compared to the bulk technique, especially in higher conversion which causes lower shrinkage stress. This situation makes the incremental technique provide better bond strength, water resorption, color stability, and lower temperature rise.Keywords: Bulk, Composite Resin, Incremental,  Physical Properties, Restoration, Restoration Technique

scholarly journals Abrasion resistance of composites polymerized by light-emitting diodes (LED) and halogen light-curing units

2006 ◽  
Vol 17 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Janisse Martinelli ◽  
Fernanda de Carvalho Panzeri Pires-de-Souza ◽  
Luciana Assirati Casemiro ◽  
Camila Tirapelli ◽  
Heitor Panzer
Keyword(s):  
Surface Roughness ◽  
Mass Loss ◽  
Abrasion Resistance ◽  
Composite Resin ◽  
Composite Resins ◽  
Halogen Lamp ◽  
Light Emitting ◽  
Halogen Light ◽  
Light Curing ◽  
Toothbrush Abrasion

This study compared the abrasion resistance of direct composite resins cured by light-emitting diodes (LED) and halogen light-curing units. Twenty specimens (12 mm in diameter; 1.0 mm thick) of each composite resin [TPH (Dentsply); Definite (Degussa); Charisma (Heraus Kulzer)] were prepared using a polytetrafluoroethylene matrix. Ten specimens per material were cured with the LED source and 10 with the halogen lamp for 40 s. The resin discs were polished, submitted to initial surface roughness reading (Ra initial - mum) in a roughness tester and stored in water at 37°C for 15 days. The specimens were weighed (M1) and submitted to simulated toothbrushing using slurry of water and dentifrice with high abrasiveness. After 100 minutes in the toothbrushing simulator, the specimens were cleaned, submitted to a new surface roughness reading (Ra final - mum) and reweighed (M2). Mass loss was determined as the difference between M1 and M2. Data were recorded and analyzed statistically by one-way ANOVA and Tukey Test at 5% significance level. The composite resin with greater size of inorganic fillers (TPH) showed the lowest mass loss and surface roughness means, indicating a higher resistance to toothbrush abrasion (p<0.05). Definite cured with LED presented the least resistance to toothbrush abrasion, showing the highest means of surface roughness and mass loss (p<0.05). The LED source did not show the same effectiveness as the halogen lamp for polymerizing this specific composite resin. When the composite resins were cured a halogen LCU, no statistically significant difference was observed among the materials (p>0.05). It may be concluded that the type of light-curing unit and the resin composition seemed to interfere with the materials' resistance to abrasion.

scholarly journals Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities

2017 ◽  
Vol 18 (1) ◽  
pp. 39-43
Author(s):  
Fahad Alkhudhairy
Keyword(s):  
Wear Resistance ◽  
Light Intensity ◽  
High Intensity ◽  
Composite Resin ◽  
Surface Loss ◽  
Low Intensity ◽  
Significant Difference ◽  
Restorative Materials ◽  
Light Curing ◽  
Curing Light

ABSTRACT Introduction The aim of this study was to assess the wear resistance of four bulk-fill composite resin restorative materials cured using high- and low-intensity lights. Materials and methods Twenty-four samples were prepared from each composite resin material (Tetric N-Ceram, SonicFill, Smart Dentin Replacement, Filtek Bulk-Fill) resulting in a total of 96 samples; they were placed into a mold in a single increment. All of the 96 samples were cured using the Bluephase N light curing unit for 20 seconds. Half of the total specimens (n = 48) were light cured using high-intensity output (1,200 mW/cm2), while the remaining half (n = 48) were light cured using low-intensity output (650 mW/cm2). Wear was analyzed by a three-dimensional (3D) noncontact optical profilometer (Contour GT-I, Bruker, Germany). Mean and standard deviation (SD) of surface loss (depth) after 120,000 cycles for each test material was calculated and analyzed using one-way analysis of variance (ANOVA) with a significance level at p < 0.05. Results The least mean surface loss was observed for SonicFill (186.52 µm) cured using low-intensity light. No significant difference in the mean surface loss was observed when comparing the four tested materials with each other without taking the curing light intensity into consideration (p = 0.352). A significant difference in the mean surface loss was observed between SonicFill cured using high-intensity light compared with that cured using low-intensity light (p < 0.001). Conclusion A higher curing light intensity (1,200 mW/cm2) had no positive influence on the wear resistance of the four bulk-fill composite resin restorative materials tested compared with lower curing light intensity (650 mW/cm2). Furthermore, SonicFill cured using low-intensity light was the most wearresistant material tested, whereas Tetric N-Ceram cured using high-intensity light was the least wear resistant. Clinical significance The wear resistance was better with the newly introduced bulk-fill composite resins under low-intensity light curing. How to cite this article Alkhudhairy F. Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities. J Contemp Dent Pract 2017;18(1):39-43.

scholarly journals Effect of dispensing method and curing modes on the microleakage of composite resins

2020 ◽  
Vol 32 (1) ◽  
pp. 9-15
Author(s):  
Bahar J Selivany ◽  
Muhand A Khadim ◽  
Dara H Saeed ◽  
Abdulhaq A Suliman
Keyword(s):  
Composite Resin ◽  
Conventional Technique ◽  
Composite Resins ◽  
Conventional Group ◽  
Class V ◽  
Dye Penetration ◽  
Light Curing ◽  
Blue Solution ◽  
Nail Varnish ◽  
Composite Restoration

Background: Vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. This study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes Materials and methods: Standard Class V cavities were prepared on the buccal surface of sixty extracted premolars. Teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (LED-Ramp, LED-Fast and Halogen Continuous modes). Cavities were etched and bonded with Single Bond Universal then restored with Filtek® Z350 (3M ESPE, USA). In the vibration group, condensation was done using CompothixoTM (Kerr, Switzerland). In the conventional group, condensation was done with hand plugger. Curing modes for all groups were LED-Ramp, LED-Fast and halogen continuous modes, respectively. Samples stored in distilled water at 37°C for seven days, and painted completely with two layers of nail varnish with only 1 mm around the composite restoration left. Samples were thermocycled, immersed in 2% methylene blue solution for 3 hours, and sectioned longitudinally. Dye penetration was assessed under a stereomicroscope. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests with p <0.05 considered significant. Results: Vibration group showed less microleakage (P=0.028). In the conventional group there were no differences by using different curing modes (P=0.277). In the vibration group no differences were found between LED-Ramp and LED-Fast mode (P=0.989). However, there were significant differences between LED-Fast and halogen (P=0.05) and between LED-Ramp and halogen group (P=0.001). Microleakage scores of all cervical walls were higher than the occlusal walls (P=0.001). Occlusal walls leakage for conventional and vibration groups were not different (P=0.475), while there were significant differences between them at cervical walls (P=0.001). Conclusion: Vibration with LED-Ramp curing mode may decrease marginal leakage of composite restoration placed in Standard Class V tooth preparations. Keywords: Composite resin, Vibration, Condensation, Compothixo, Microleakage,

scholarly journals Effect of LED and Argon Laser on Degree of Conversion and Temperature Rise of Hybrid and Low Shrinkage Composite Resins

2016 ◽  
Vol 10 (1) ◽  
pp. 538-545 ◽  
Author(s):  
Ayob Pahlevan ◽  
Masumeh Hasani Tabatabaei ◽  
Sakineh Arami ◽  
Sara Valizadeh
Keyword(s):  
Energy Density ◽  
Temperature Rise ◽  
Composite Resin ◽  
Argon Laser ◽  
Composite Resins ◽  
Degree Of Conversion ◽  
Light Curing ◽  
Higher Temperature ◽  
Laser Curing ◽  
One Way Anova

Objectives:Different light curing units are used for polymerization of composite resins. The aim of this study was to evaluate the degree of conversion (DC) and temperature rise in hybrid and low shrinkage composite resins cured by LED and Argon Laser curing lights.Materials and Methods:DC was measured using FTIR spectroscopy. For measuring temperature rise, composite resin samples were placed in Teflon molds and cured from the top. The thermocouple under samples recorded the temperature rise. After initial radiation and specimens reaching the ambient temperature, reirradiation was done and temperature was recorded again. Both temperature rise and DC data submitted to one-way ANOVA and Tukey-HSD tests (5% significance).Results:The obtained results revealed that DC was not significantly different between the understudy composite resins or curing units. Low shrinkage composite resin showed a significantly higher temperature rise than hybrid composite resin. Argon laser caused the lowest temperature rise among the curing units.Conclusion:Energy density of light curing units was correlated with the DC. Type of composite resin and light curing unit had a significant effect on temperature rise due to polymerization and curing unit, respectively.

Study Regarding the Influence of Polymerization Mode of Light Unit on Surface Microhardness of Composite Resins

2015 ◽  
Vol 754-755 ◽  
pp. 271-275
Author(s):  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Manuela Cristina Perju ◽  
Andrei Victor Sandu ◽  
Sorin Andrian
Keyword(s):  
Vickers Hardness ◽  
High Intensity ◽  
Composite Resin ◽  
Surface Hardness ◽  
Pulse Mode ◽  
Composite Resins ◽  
Surface Microhardness ◽  
Mean Values ◽  
Inner Diameter ◽  
Composite Samples

The aim of the study was to compare the surface microhardness of composite resins polymerized in different mode of light unit. Three commercial composite resins: Charisma (Heraeus Kulzer Co.), Filtek Z 250 (3M ESPE Co.) and G-aenial Anterior (GC Company Co.), were used in this study. Fifteen samples of each material were obtained by placing the composite resin in plastic rings having 2 mm high and 6 mm inner diameter. All composite samples were cured using blue light-emitted diode G 0010 (SKI, China). Five samples were cured using ramp mode of the light unit, five samples were cured using single light: high intensity (constant) mode and five samples were cured using pulse mode. The samples were finished and polished and then stored in distilled water, at room temperature for 48 hours. The samples were subjected to microhardness evaluation using microhardness tester (Micro-Vickers Hardness System CV-400DMTM, CV Instruments Namicon). A 50 g load was applied through a Vickers indenter. For each sample three indentations were made in different areas of the sample and the value of Vickers hardness was calculated as a mean result of the three recordings. Statistical Mann-Whitney U test and Kruskal-Wallis test were used to compare the values of surface hardness. Polymerization of all three composite resins using pulse mode leaded to significantly lowest mean hardness values and single light high intensity mode to the highest values. Filtek Z250 composite resin showed the highest microhardness mean values in all three polymerization mode and Charisma the lowest values. Surface microhardness of composite resins is influenced by different modes of light unit. Single light high intensity mode of polymerization leaded to the highest values of microhardness, followed in descending order by ramp and pulse mode. The best results regarding the surface microhardness was recorded for Filtek Z250composite resin, followed in descending order by G-aenial Anterior and Charisma.

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